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Population Dynamics of the St. Marys River Fish Community 1975 ...

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Table 8. Catch-per-unit-<strong>of</strong>-effort (CPUE) <strong>of</strong> nor<strong>the</strong>rn pike by age and mean length-at-age at capture for <strong>the</strong> <strong>St</strong>. <strong>Marys</strong> <strong>River</strong>, August - September,<br />

2006. For comparison, mean length-at-age is included from past surveys and <strong>the</strong> Michigan state average length-at-age 1 as well as <strong>the</strong> Ontario Lake<br />

Huron 2002 North Channel (ON NC) average 2 . Unit <strong>of</strong> effort is one 304.8 m gillnet set. Growth index 1 compares length-at-age to state average<br />

and <strong>the</strong> 2006 year to <strong>the</strong> NC average. It excludes age groups represented by less than 5 specimens. All lengths and <strong>the</strong> growth index are in mm.<br />

CPUE values by age may omit some un-aged fish and <strong>the</strong>refore may not total to <strong>the</strong> overall CPUE for this species as reported in Table 2.<br />

Age<br />

Parameter 0 1 2 3 4 5 6 7 8 9 10 11 12 13<br />

Mean<br />

age<br />

Mean<br />

length<br />

Growth<br />

index<br />

Number 3 30 18 8 9<br />

CPUE 0.07 0.71 0.43 0.19 0.21<br />

Frequency (%) 4.4 44.1 26.5 11.3 12.7<br />

Mean length<br />

This survey (2006) 269 429 528 601 642 1.8 491 +13<br />

2002 survey 250 371 455 564 620 669 2.4 477 -34<br />

1995 survey 399 465 538 605 621 722 918 1033 -39<br />

1987 survey 407 468 515 575 672 726 752 754 -39<br />

MI average 422 511 579 635 683 732 780<br />

ON NC 2002<br />

377 483 580 657 749 706 +26<br />

average<br />

1 From Schneider et al. (2000)<br />

2 Ontario MNR, unpublished data<br />

30

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